1. Diskin et al. studied common breath metabolites such as ammonia, acetone, isoprene, ethanol, and acetaldehyde in five subjects over a period of 30 days. Each day, breath samples were taken and analyzed in the early morning on arrival at the laboratory. For subject A, a 27-year-old female, the ammonia concentration in parts per billion (ppb) followed a normal distribution over 30 days with mean 509 and standard deviation 78. [8 marks] a. What is the probability that on a random day, the subject's ammonia concentration is between 509 ppb and 520 ppb? b. What is the probability that on a random day, the subject's ammonia concentration is less than 450 ppb? c. What is the probability that on a random day, the subject's ammonia concentration is between 450 ppb and 550 ppb? d. What is the probability that on a random day, the subject's ammonia concentration is greater than 500 ppb?